One-dimensional wave theory analysis of factors and characteristics influencing errors in two-wave method data processing in SHPB  

SHPB试验中二波法数据处理误差影响因素与特性的一维波理论分析

作　　者：Minghui Ma Guangfa Gao 马铭辉;高光发

机构地区：[1]School of Mechanical Engineering,Nanjing University of Science and Technology,Nanjing 210094,China

出　　处：《Acta Mechanica Sinica》2025年第1期128-140,共13页力学学报(英文版)

基　　金：supported by the National Natural Science Foundation of China (Grant Nos.U2341244,12172179,and 11772160);the Postgraduate Research&Practice Innovation Program of Jiangsu Province.

摘　　要：A simplified calculation of the specimen’s stress-strain curve is generally conducted using the two-wave method by the split Hopkinson pressure bar(SHPB),which aligns the onset of the transmitted and reflected waves.However,this approach neglects the travel time of elastic waves within the specimen.Considering the travel time of elastic waves,this study quantitatively investigates the error characteristics and patterns of stress,strain,and strain rate in the specimen under different conditions using the theoretical two-wave method,and compares the results with those obtained using the onset-aligned twowave method.The study reveals that the stress-time curves derived from the theoretical two-wave method are lower than the actual stress curves,whereas those obtained from the onset-aligned two-wave method are consistently higher than the actual stress curves,with the stress deviation approximating a constant value when the dimensionless time exceeds 2.0.The starting point of the stress-strain curves obtained by the theoretical two-wave method is not zero but a point on the strain axis,whereas the onset-aligned two-wave method always starts at zero.However,the slopes of the stress-strain curves obtained by both methods differ from the actual Young’s modulus of the material,and functional relationships between the slopes and the actual Young’s modulus are provided.This research offers theoretical guidance for the refined design of SHPB experiments and the accurate processing of data.基于SHPB的平面波假设,一般采用将透射波和反射波的起点对齐的二波法对试件的应力应变曲线进行简化计算,然而这种处理方法忽略了弹性波在试件中的运动时间.考虑到弹性波在试件中的运动时间,定量研究了采用理论二波法计算时试件在不同情况下的应力、应变和应变率的误差特征和规律,并和起点对齐二波法的计算结果进行了比较.研究表明:理论二波法所得到的应力时程曲线小于实际应力曲线,但起点对齐二波法反之始终大于实际应力曲线,当无量纲时间大于2.0时应力偏差近似恒值.理论二波法给出的应力应变曲线的起点并非零点,而是应变坐标轴上的一点,起点对齐二波法给出的应力应变曲线的起点均为零点,但两种方法得到的应力应变曲线的斜率均和材料的真实杨氏模量有所差异,并给出了两种方法的斜率和材料真实杨氏模量的函数关系式.在此基础上,研究了两种方法给出的应力应变曲线的偏差特征.研究为SHPB试验的精细化设计与数据的准确处理提供理论参考.

关 键 词：SHPB Stress wave effect Assumption of stress uniformity Dynamic stress-strain curve 

分 类 号：O347.1[理学—固体力学]